Isuzu Trooper Owners Club UK™

[Gribble]

Manifold absolute pressure sensor  - reads the turbo boost for the ecu. wont stop it going but would stop it going well !

Lives on the inlet manifold left of the erg valve and has one pipe going to the inlet manifold.

Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure. The MAP sensor
signal voltage to the ECM varies from below 2 volts at idle
(high vacuum) to above 4 volts.
The MAP sensor is used to determine the following:

Boost pressure for injector control.

Barometric pressure (BARO).

Pub Time now lol
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2 New Troopers !

[Google]

[Xeffin1]

Cheers Gribble, I hope you enjoyed your pint or six lol

[Browndoff]

You could probably clear the MAP-Sensor fault by cleaning the little tube that runs from it to the Inlet-Manifold and the metal Spigot which runs into the manifold. I do mine with a little twist of tissue-paper, poked in and out until it comes out clean. Nasty job  - but it makes it run much better!

As mentioned - the MAP-Sensor SHOULD NOT prevent starting - so it's NOT the main problem!

Recently, though, Gribble mentioned a car which SOMETIMES would not start - and other times did so without any fuss. THAT problem, as he found it, was due to a stuck throttle-valve. It's just possible that YOURS is more consistently stuck...............?? In another context, Eithan has even recommended REMOVING the disc of the throttle-assembly altogether [a very EASY job!] - wouldn't it be great if that were your only problem!!

[Xeffin1]

Thanks Browndoff, another thing to try this weekend, Thanks will let you know what happens.

[Xeffin1]

OK another couple of hours on the Trooper LOL.

Non Starting issue re cap:-

Trooper started with a little easy start and continued to run for 15 minutes revving and ticking over perfect then abruptly stuttered then stopped, it has not started since.

Things done so far...
1      White wire cut -  No change
2       Brake light fuse checked  -  OK
3      Extra 2 liters of oil added  -  
4      Fuel primer pump checked  -  All ok and pumping well, fuel lifted from tank no bubbles that i can see
5      Flash test carried out  - only a code 34 Map Sensor low voltage, would not prevent a start, & white wire re connected
6      ORPCV removed and checked for smooth operation of plunger  -  All OK
7      Throttle valve checked moves smoothly by hand and was open when i uncovered it, it did have a silicone gasket i replaced it with a paper one.

When cranking engine light goes out so i presume the Crank and Cam sensors are talking, the cranking speed is quite fast and when i release the key the engine oil pressure reads about 40lbs 1/4 of the gauge.

To get hold of someone with a Tech 2 would involve a lot of dosh as trooper dan is in leeds, working it out from the rates it would caost about £150.00

Can anyone give me an idea what to try next??


Cheers

[eithan h]

hpop or the ecu itself looking at this list!

[Gribble]

Might be the ropcv as its wants gas to start ,it is T2 time now really .
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2 New Troopers !

[Xeffin1]

Well, Tried a known working ORPCV it was a no go, Dan came along and tech 2'd it there were no faults at all, the click test was fine too. Dan sent me another known working HPOP, I have got so far with taking it off, I have removed the large oil feed pipe to cam cover and presume i need to remove the lower one which has a large domed nut on the end which is partially blocked by the engine mount, what size spanner takes it off and is it best to tackle from above, once that is off i should be able to get at the other pipe work and then remove the bracket bolted into the block.
  Is there a how to do page on the forum anywhere that someone recalls seeing, I don't want to re invent the wheel or give myself extra grief by doing something i should not.

Cheers

[Mike Rosie]

Have you proved that you are not getting oil pressure at the rail ?
I had a similar problem and tried a different ROPCV from my other trooper but no luck.
I fitted a gauge to the rail where the pressure sensor mounts and measured the pressure directly.
You can measure the voltage from the sensor at the ecu which gives a good indication of what's going on
I eventually got another ROPCV and fitted that and got her started.
I can only suspect I never gave the first attempt long enough.
My original valve also appeared free.
Trooper is now running great but cranks a bit to long on start up so I will be chasing that down now that I got a tech 2.
You can also look at the injector pulse if you have the right type of meter.

[Xeffin1]

yes I am getting oil pressure just no fuel, i suspect its the lift pump that's gone kaput, nothing really comes out of the domed nut at the top (17mm one). I have a known working ORPCV and it still does not want to know, i have good pressure in the manual pump and have tested it so know it works.
I have the pump halfway dismantled so just wanted any pointers / advice as sometimes you undo things maybe you need not have to. I wondered if anyone posted a how to remove and replace.

Cheers for that though.

[eithan h]

what oil pressure are you getting?

[Xeffin1]

Hi Eithan,

When Dan had the T2 on he checked that there was a return flow, as to what the actual pressure going to the injectors is i don't know. Cracking the domed nut for the fuel at the top produced nothing though. Dan supplied the working ORPCV with no joy and has forwarded a known working HPOP so i am at the stage of taking my old one off and replacing it. I read on the forum that there is no need to take the timing belt off so have left that in situ I have removed 2 bolts that were next to the pulley for the pump, the top large pipe is removed but need to remove the bottom large pipe with a large domed nut, I am struggling to get at that and with not knowing size of nut and being difficult to get at ( These nuts are huge and industrial in size ) once thats gone i intend to remove the smaller fuel feed pipe and the other large one off the back of the pump i should then be able to remove the steel bracket and then remove the last 2 outer bolts on the pump and consider drawing the pump off.

Any suggestions you may have would be most welcome, i want to get this right first time LOL

[kennymac]